The thermal degradation of polychloroprene-II study of the products of degradation

Studies have been made of the gaseous and liquid products and the involatile residue from the degradation of polychloroprene. Programmed heating was used; below 400° in addition to hydrogen chloride, small amounts of ethylene and a trace of chloroprene were detected in the volatile products. Above 400°, methane became a significant product; smaller amounts of hydrogen, ethylene and propylene were present. The liquid products were not fully characterized: the complex mixture contained products, which might be chloroprene dimers, and less volatile components containing aromatic structures. The involatile residue of partial degradation showed similarities to that obtained in PVC degradation, but differed in giving a clear indication of methyl groups. Conjugation was found to be much less extensive than in PVC after dehydrochorination; triene structures predominated, and there was little contribution from structures with 12 or more double bonds in conjugation.